Vehicle headlamp shield

ABSTRACT

This invention relates to a shield to be used in a vehicle headlamp comprising a concave base member with curved or planar side wall sections having a channel member positioned in the central portion of the base member with the base of the channel projecting inwardly from the concave surface to prevent the direct light of the low beam filament from being projected or reflected forwardly as glare or uncontrolled light. The shield also acts to reduce and disperse the light it reflects thereby preventing excessive redirected light in unwanted regions.

United States Patent 1 Thiry 1 VEHlCLE HEADLAMP SHIELD [75] Inventor:William G. Thiry, Oley, Pa.

[73] Assignee: Wagner Electric Corporation,

Newark, NJ.

[22] Filed: Mar. 13, 1972 [2]] Appl. No.: 234,294

[52] 0.8. CI 240/46.0l, 240/4125, 240/46.55,

313/117 [51] Int. Cl. F2lv 11/00 [58] Field of Search 240/41.2, 41.25,

[56] References Cited UNITED STATES PATENTS 1,205,361 11/1916 Lakin240/4135 C 1,647,613 11/1927 Fredette 1,877,978 9/1932 Sarver 3,136,9146/1964 Jayne et a1 2,876,375 3/1959 Marsh 313/117 3,020,435 2/1962 Mead313/117 1,738,304 12/1929 Laurent 240/4135 C 1,583,216 5/1926 Wompey240/4135 C 1,954,978 4/1934 Aldrich 240/4655 Primary ExaminerSamuel S.Matthews Assistant ExaminerRichard M. Sheer Attorney-William D. Lucas etal.

[57] ABSTRACT This invention relates to a shield to be used in a vehicleheadlamp comprising a concave base member with curved or planar sidewall sections having a channel member positioned in the central portionof the base member with the base of the channel projecting inwardly fromthe concave surface to prevent the direct light of the low beam filamentfrom being projected or reflected forwardly as glare or uncontrolledlight. The

shield also acts to reduce and disperse the light it reflects therebypreventing excessive redirected light in unwanted regions.

14 Claims, 6 Drawing Figures VEHICLE HEADLAMP SHIELD In recent yearsshields for vehicle headlamps have been designed to compensate forvehicle styling changes which have lowered the headlamp and placed it tothe rear of highly polished surfaces such as bumpers. Without a properlydesigned shield, the direct light of the low beam filament is reflectedoff these highly polished surfaces resulting in uncontrolled glare whichespecially impairs driver vision in fog, mist, rain or snow. A typicaldesign is shown in U.S. Pat. No. 3,136,914, which describes a shieldwith a central aperture so arranged that the remaining solid portionscut off the direct light from the low beam filament at certain anglesabove and below the central axis of the filament. Such apertures are cutto permit direct light to pass from the filaments in the forwarddirection in the belief that road lighting ahead of the car is improved.

It is also customary to provide a shield that is a truncated cone orportion of a sphere which may be provided with concentric circularcorrugations. In these cases, the surface of the shield in the vicinityof the op tical axis of the lamp is placed at approximately 90 to thisaxis.

In these types of shields, no provision is made for the light reflectedfrom the shield and such light is redirected and results in unwantedillumination especially in the regions designated at 1 up and to 90 upin the SAE specification SAE J579a, Sealed Beam Headlamp Units for MotorVehicles, P723, SAE Handbook, New York, 1972.

It is therefore the principal object of this invention to provide ashield which will not only eliminate direct light from being reflectedfrom highly polished surfaces forward of the headlamp, but also toreduce and disperse the light reflected from the shield, therebyreducing unwanted illumination and glare, especially in fog, mist, rainor snow.

Briefly, the present invention comprises a shield constructed without anopening for light that moves directly forward from the low beam lampfilament. Open ings may be provided at the opposite sides of the shieldto provide side lighting in the near vicinity of the vehicle as an aidfor detecting pedestrians, or obstacles, and for cornering.

The shield comprises a concave base member which may be curved, orspherical, or a combination thereof, or it may contain planar portionsin combination with curved and/or spherical portions. Preferably thebase member is in the general form of a dish or cup having a channelmember positioned in the central portion of the base member so that thebase of the channel projects inwardly from the concave surface. Whenopenings are provided at opposite sides of the base member to provideside lighting, the side wall of the base member is divided into twooppositely disposed sections joined at opposite ends of the openings bythe channel member and base member respectively. The side wall sectionsof the base member may have any desired configuration but best resultsare achieved with spherical side wall sections or side wall sectionshaving a smooth curve, either alone or in combination with planarportions. The channel may be in the general form of a U but best resultsare achieved with a V-shaped channel member, the legs of which areconnected to the planar portions of the side wall sections and formincluded interior angles with the planar portions of the side wallsections of between about ninety to one hundred and thirty five degrees.

The best dispersion of light is achieved by the V- shaped channel memberwhich does not have any flat surface positioned normal to the axis ofthe filament of the lamp. Furthermore, a portion of the light reflectedfrom the legs of the V will be directed against the side wall of thebase member and thereby doubly reflected within the shield beforereaching the main reflector of the lamp. This double reflectiontremendously reduces the intensity of the light and assists in achievinga wider dispersion of what is ordinarily forward light from the low beamfilament. When the interior angle formed by the V and a planar portionof a side wall section is less than there is a tendency to reflect lightinto the heel of the reflector which gives objectionable glare ininclement weather and when the angle is greater than there is a tendencyfor all the light reflected from the legs of the V to be directedtowards the reflector, especially into the heel portion, without firstbeing reflected from the side wall sections.

When the interior angle is formed by the planar portion of a side wallsection and a U-shaped channel member, or a curved side wall section anda V-shaped channel member, or a curved side wall section and a U-shapedchannel member, the curved side wall section or the curve of the U, orboth, are adjusted to obtain reflections which are equivalent to thoseobtained with a V-shaped channel member and the planar portion of a sidewall section forming an interior angle of from 90-135. This may bereadily done by adjusting the respective curved surface or surfaces toobtain acceptable light intensities corresponding to interior anglesformed by a V-shape channel member and the planar portion of a side wallsection of from 90-135, especially in the regions designated as l up and10 up to 90 in SAE Specification SAE J579.

Further details of the invention may be readily understood by referenceto the drawing which illustrates preferred embodiments and in which:

FIG. 1 is a front view of one preferred embodiment of the shield.

FIG. 2 is a side view of the shield of FIG. 1.

FIG. 3 is a side cross-section of the shield of FIG. 1 taken on line 3-3showing the light distribution relationship with the headlamp reflector.

' FIG. 4 is a front view of a modified embodiment of the shield in FIG.1.

FIG. 5 is a side view of a modified embodiment of the shield in FIG. 1.

FIG. 6 is a side view of a modified embodiment of the shield in FIG. 1.

In the drawings the same number is used for an identical part wheneverit occurs.

Referring now to the drawings in detail and in particular to FIGS. 1 and2, 20 is a headlamp shield made up of a V-shaped center channel section22 with each of the lateral surfaces 24 in opposite legs of the Vconnected to a side wall section 28 of the concave base member 30.Openings 32 are provided on both sides of the center channel section 22between the oppositely disposed side wall sections 28. The side wallsections 28 are joined together at opposite ends of the openings 32 bythe channel section 22 and by a connecting portion 33 of the base member30. Each side wall section 28 is made up of a planar surfaced centerportion 34 and a curved side portion 36. The side wall sections 28 forma concavity within which lies the base of channel section 22. The baseor edge 38 formed at the junction of the lateral faces 24 of the channelsection 22 protrudes into the volume delineated by the concave surfaceof the side wall sections 28 of the base member 30. When looking intothe headlamp toward the reflector, the low beam filament 40 ispreferably centered on the channel section 22 and positioned above thechannel edge 38. The high beam filament 42 is preferably offset from thechannel section 22 and located below the channel edge 38. The filamentsare preferably positioned outside the concave surface of the base member30 as shown in FIG. 3. The arm 44 is used to mount the shield inposition in the lamp in conventional manner well-known in the art.

The operation of the shield will be explained with reference to FIG. 3.The low beam filament 40 is located outside the concave surface of theshield and all of the light rays which move directly forward from thefilament strike the shield. The headlamp reflector surface is 45 and 46is the heel portion of the reflector. The optical axis of the lamp isshown at 48. The headlamp lens is designated by 80. R through R; arelight rays emitted at different angles from the low beam filament 40towards the shield 20. S denotes a ray which is singly reflected fromthe shield, and D denotes a ray which is doubly reflected from theshield. The manner in which the light will be reflected from the shielddepends upon the angle b formed by the side wall planar portion 34 andthe channel lateral face 24, and the angle a formed by the channellateral faces 24 as shown in FIG. 2. In the preferred embodiment, anglea is 126 and angle b is 1 18. As the value of these angles is changedthe surface area of double reflection will change. In the presentembodiment, approximately 60 percent of the surface of the channelmember effects double reflection.

Rays such as R and R and R and R which initially strike the side wallplanar portion section 34, are singly reflected from the shield surfaceto the reflector. Rays R and R are directed outside of the heel portion46 of the reflector surface 45 and rays such as R and R are directedinto the heel portion and are again reflected into the shield. All raysinitially striking the side wall planar portion 24 of the shield can begrouped into rays such as R and R and rays such as R and R Rays such asR and R; which initially strike the channel lateral faces 24 ofthechannel member adjacent the planar portion 34 of the said side wallsections 28 are doubly reflected from the shield before being directedto the headlamp reflector 45.

Rays such as R, which strike the lateral face 24 just beyond the area ofdouble reflection, are singly reflected from the shield, but similar torays R and R are directed outside of the heel portion 46 of thereflector 45.

Rays such as R and R which initially strike the lateral face 24 in thearea of the edge 38, are also singly reflected and directed outside ofthe heel portion 46.

The light reflected from the shield surface can then be classified intothree types: l double reflected light; (2) singly reflected light whichis directed into the heel portion of the reflector and redirectedtowards the shield; (3) singly reflected light which is directed outsidethe heel portion of the reflector.

A double reflection reduces the light intensity reaching the reflectingsurface to a small percentage of that of direct forward light. Forexample, if the normally coated dull surface of the shield reflects 1percent of the light impinging on it, double reflection would result inonly 0.0001 of the original intensity reaching the reflector.Furthermore, the area over which the light is spread on the reflector isincreased by double reflection and this too reduces effective intensity.Rays singly reflected from the shield into the heel area will eventuallyresult in a double reflection since the reflector directs this lightback into the shield.

Rays singly reflected from the shield to outside the heel portion, suchas R R R and R are significantly diminished in intensity because theyare spread over a greater area of the reflector, resulting in arelatively large dispersion and correspondingly low intensity.

As a result the halo which would normally be observed as uncontrolledlight is significantly reduced in intensity by the use of the shield asevidenced by the reduction of light to below the maximum level allowedin the 1 up and 10 up to 90 region in SAE Specification J579a.

Referring to FIG. 4, a modified form of shield 20 is shown. Shield 50 isidentical to shield 20 except that the concave base member hasoppositely disposed conical side wall sections 52 instead of the planarand curved side wall sections of shield 20.

Similarly referring to FIG. 5, a modified form of a shield 20 is shown.Shield 60 is identical to shield 20 except that the concave base member30 has oppositedly disposed spherical side wall sections 62 instead ofthe planar and curved side wall sections of shield 20.

Referring to FIG. 6, a modified form of shield 20 is shown. Shield isidentical to shield 20 except that the channel portion 72 is U-shapedinstead of the V- shaped channel portion of shield 20.

It will be understood that it is intended to cover all changes andmodifications of the preferred forms of the invention, herein chosen forthe purpose of illustration, which do not constitute departure from thespirit and scope of the invention.

What is claimed is:

l. A shield for use in a headlamp comprising a concave base member and atrough-shaped second member formed by a pair of opposed intersectingelongated surfaces, said trough-shaped second member being positioned inthe central portion of said concave base member and at least partiallyprotruding into the volume partially enclosed by the concave surface ofsaid concave base member.

2. The shield of claim 1 wherein said second member is V-shaped.

3. The shield of claim 1 wherein said second member is U-shaped.

4. The shield of claim 1 wherein said concave base member is comprisedof oppositely disposed side wall sections which have curved and planarportions.

5. The shield of claim 1 wherein said concave base member is sphericallyshaped.

6. The shield of claim 1 wherein said concave base member is conicallyshaped.

7. The shield of claim 1 wherein openings are provided in said basemember adjacent said second member.

8. In combination with a headlamp comprising a concave reflector, aheadlamp lens, and a source of light positioned between said lens andsaid reflector, a shield opposite said source of light and positionedbetween said source of light and said lens, said shield comprising aconcave base member and a trough-shaped second member formed by a pairof opposed intersecting elongated surfaces, said trough-shaped secondmember being positioned in the central portion of said concave basemember and at least partially protruding into the volume partiallyenclosed by the concave surface of said concave base member.

9. The headlamp and shield of claim 8, wherein said source of lightcomprises at least one lamp filament and wherein said shield ispositioned so that said filament is centered relative to said secondmember and above the intersection of said elongated surfaces formingsaid second member and wherein a portion of the light from said filamentimpinges upon said shield and is doubly reflected from said shield,first from said second member to said base member and secondly from saidbase member to said concave reflector.

10. The headlamp and shield of claim 9, wherein said concave reflectorcomprises a heel portion and wherein light from said filament impingesupon said base member and is reflected in a dispersive pattern, a majorportion of the light which is so reflected being directed away from saidheel portion of said concave headlamp reflector.

11. A shield for use in a headlamp comprising a concave base memberhaving a pair of opposed, spaced apart side walls defining an openingtherebetween, a second member positioned in the central portion of saidopening between said side walls to provide spaced openings on oppositesides of said second member, each of said opposed side walls comprisinga planar portion positioned intermediate two curved portions, saidsecond member being in the general shape of a V- shaped trough havingtwo intersecting, elongated legs, each of said legs being connected toeach of said planar portions, and said second member at least partiallyprotruding into the volume partially enclosed by the concave surface ofsaid concave base member.

12. The shield of claim 11 wherein the interior angle formed by saidlegs of said V-shaped second member is 126.

13. The shield of claim 11 wherein each of the interior angles formed bysaid legs of said V-shaped second member and said planar portions ofsaid side walls is 1 18.

14. The shield of claim 13 wherein each of said angles is from about to0 i ll' t l Patent No.

(SEAL) Attest:

3 749 ,906 Dated Inventor(s) Column 1, line 27,

EDWARD M.FLETCHER,JR. Attestiflg Officer" July 31, 1973 William G. ThiryIt is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

after "10" insert--up-- Column 3, line 411+, change "24" t0-34--..

Column 4, line 11, change "R2" t0--Rl-;

Q same line, delete "R8" and insert- R5, R7--.

column 5, line elem 10 line 6) delete "headlamp".

Signed and sealed this 27th day of November 1973.

RENE D TEGTMEYER v h e Acting commisinhe'r of Patents FORM 1 0-1050(10-69)

1. A shield for use in a headlamp comprising a concave base member and atrough-shaped second member formed by a pair of opposed intersectingelongated surfaces, said trough-shaped second member being positioned inthe central portion of said concave base member and at least partiallyprotruding into the volume partially enclosed by the concave surface ofsaid concave base member.
 2. The shield of claim 1 wherein said secondmember is V-shaped.
 3. The shield of claim 1 wherein said second memberis U-shaped.
 4. The shield of claim 1 wherein said concave base memberis comprised of oppositely disposed side wall sections which have curvedand planar portions.
 5. The shield of claim 1 wherein said concave basemember is spherically shaped.
 6. The shield of claim 1 wherein saidconcave base member is conically shaped.
 7. The shield of claim 1wherein openings are provided in said base member adjacent said secondmember.
 8. In combination with a headlamp comprising a concavereflector, a headlamp lens, and a source of light positioned betweensaid lens and said reflector, a shield opposite said source of light andpositioned between said source of light and said lens, said shieldcomprising a concave base member and a trough-shaped second memberformed by a pair of opposed intersecting elongated surfaces, saidtrough-shaped second member being positioned in the central portion ofsaid concave base member and at least partially protruding into thevolume partially enclosed by the concave surface of said concave basemember.
 9. The headlamp and shield of claim 8, wherein said source oflight comprises at least one lamp filament and wherein said shield ispositioned so thaT said filament is centered relative to said secondmember and above the intersection of said elongated surfaces formingsaid second member and wherein a portion of the light from said filamentimpinges upon said shield and is doubly reflected from said shield,first from said second member to said base member and secondly from saidbase member to said concave reflector.
 10. The headlamp and shield ofclaim 9, wherein said concave reflector comprises a heel portion andwherein light from said filament impinges upon said base member and isreflected in a dispersive pattern, a major portion of the light which isso reflected being directed away from said heel portion of said concaveheadlamp reflector.
 11. A shield for use in a headlamp comprising aconcave base member having a pair of opposed, spaced apart side wallsdefining an opening therebetween, a second member positioned in thecentral portion of said opening between said side walls to providespaced openings on opposite sides of said second member, each of saidopposed side walls comprising a planar portion positioned intermediatetwo curved portions, said second member being in the general shape of aV-shaped trough having two intersecting, elongated legs, each of saidlegs being connected to each of said planar portions, and said secondmember at least partially protruding into the volume partially enclosedby the concave surface of said concave base member.
 12. The shield ofclaim 11 wherein the interior angle formed by said legs of said V-shapedsecond member is 126*.
 13. The shield of claim 11 wherein each of theinterior angles formed by said legs of said V-shaped second member andsaid planar portions of said side walls is 118*.
 14. The shield of claim13 wherein each of said angles is from about 90* to 135*.